-LRB- CNN -RRB- In Moscow on February 27 , 2015 , a lone gunman killed Boris Nemtsov , a former deputy prime minister and a powerful and charismatic opposition leader who stood as an alternative to Vladimir Putin . In Leningrad on December 1 , 1934 , a lone gunman killed Sergey Kirov , a powerful Bolshevik who stood as an alternative to Josef Stalin .

Stalin 's involvement in the murder was denied , and never proved . It goes without saying that the Kremlin also was quick to deny Putin 's involvement in Nemtsov 's death .

The parallels are worth considering . The murder of Kirov marked the beginning of the great purges , the period in which high-level elites were so thoroughly `` cleansed '' that the USSR stood unprepared for Hitler 's invasion .

Similarly today , Putin 's actions in Ukraine and his refusal to share power with a modernizing elite has condemned Russia to another generation of economic backwardness and political isolation .

Of course , Kirov was n't the first political opponent to fall , any more than Nemtsov was . Rival political party leaders had been sent by Lenin to camps in the 1920s , and opposition political movements , including in Ukraine , had struggled to defeat Bolshevik collectivization in the early 1930s . But this was the first top-level political assassination of a person who could have become party leader .

Similarly under Putin , political opponents have been killed , like journalist Anna Politkovskaya and Alexander Litvinenko , but they did not aspire to the presidency . And certainly much of the Putin era has been absorbed with the suppression of opposition political movements , whether in Russia , by keeping rival party leaders from registering for elections , or abroad , by invading Georgia , Crimea and eastern Ukraine to prevent democratic regimes from succeeding in neighboring states . In the death of Nemtsov , irrespective of who is ultimately found responsible , we once again have the assassination of a person who could have become the leader of the country .

Stalin 's search for Kirov 's murderers led to a second set of crimes , the escalation of repression against the Old Bolsheviks and the show trials of the mid-1930s . Over a dozen of the founding members of the Bolshevik Party were found guilty of complicity in the murder in trumped-up show trials and executed .

The question now becomes whether Kremlin 's leaders imagine that they can take the country down a similar path of isolation and ultimate destruction ? Or more likely , is the Kremlin thinking at all , or just allowing the terrible logic of this system they have created to unfold ? When the Kremlin publicly labels the opposition leaders as enemies , and spews out nothing but hatred toward those who have a right to demand freedom , then killings -- irrespective of who pulled the trigger -- are a logical result .

The Putin regime has succeeded over the last 15 years in establishing a regime that historically is unparalleled in its thievery . Nemtsov himself had been the first person to start a systematic analysis of Putin 's corruption that , he claimed , includes the building and renovation of 20 palaces , the receipt of $ 700,000 in watches , his unlimited access to yachts , planes , and a Kremlin property management department with a staff of more than 60,000 , and an annual presidential office budget of $ 2.41 billion . This all leaves aside the billions he is reported to have stashed abroad .

The regime hides successfully behind Kremlin-controlled patriotism and expansionism , making its actions in Ukraine out to be a response of local Russian-speaking populations to NATO aggression in support of a fascist junta in Kiev . The perfidy of the regime is quite unparalleled since Hitler hid his expansionism behind the desire to reunite German-speakers in the Sudetenland .

There is however an optimistic side . The population in Russia as a whole and in the large cities of Moscow and St. Petersburg in particular is not like the first-generation peasants of the Stalin era . They have traveled , they know what rule-of-law systems look like , and they know what property protection feels like . They can -LRB- for now -RRB- still connect with each other on social media .

Twitter , Facebook , Instagram , and YouTube are all alive with information , commiserations , and expressions of extreme anger against the Kremlin . Nemtsov had thousands of followers on social media , and many of his friends also have thousands of followers . Other opposition leaders like Aleksey Navalny , Ilya Yashin , Ksenya Sobchak , and many more remain , and they are both shocked and defiant .

Former prime minister Mikhail Kasyanov wrote on his blog : `` Bastards , you killed my friend in the center of Moscow ... with four bullets , to make the point to all of us free-thinking people ... The country is rolling off the cliff . '' The march against the war in Ukraine Nemtsov had planned for Sunday has been rescheduled as a march in his memory . One can only hope it will attract large numbers .

The spokesman for the Investigative Committee , Vladimir Markin , cautioned the press not to jump to conclusions and then proceeded to put up a bewildering array of possible motives that included everything except Kremlin jealousy : He called the act a political provocation perhaps perpetrated by Islamic extremists angered over his stand on the Charlie Hebdo killing ; or a `` sacral sacrifice '' by the opposition itself to destabilize the country ; or related to his views on the Ukrainian war ; or a business conflict ; or an assault related to his personal life . The fact that Nemtsov 's girlfriend was Ukrainian and she was with him when he died was immediately picked up by Russian media .

Putin called the assassination an apparent `` contract killing '' and stated he was taking charge of the investigation . And despite the fact that initial eyewitness reports stated that the killers were driving a white car without license plates , by noon the next day , RT was claiming that the car had been found , now with license plates from the Muslim republic of Ingushetia .

The sad fact is that Western powers did not understand the significance of the killing of Kirov . Let 's hope that this time they will see Nemtsov 's death as the `` shot that was heard around the world '' and mobilize to deter further Russian oppression and expansionism .

President Obama quickly condemned the murder and stated that `` I admired Nemtsov 's courageous dedication to the struggle against corruption in Russia and appreciated his willingness to share his candid views with me when we met in Moscow in 2009 . '' That would mean providing all forms of assistance to prevent the failure of Ukrainian democracy , a dream for which Nemtsov could well have died .

How to help the Russian opposition depends on whether they will be able to help themselves in the weeks to come . No one would want to be in their shoes . But standing with them in their insistence -- echoing Nemtsov -- that Putin 's authoritarian regime is based on massive corruption , will be more important than ever .

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Russian opposition leader Boris Nemtsov gunned down in Moscow

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Karen Dawisha asks if there 's a parallel to famous murder of Stalin 's rival in the 1930s